Add oil to saucepan. Saute onion and garlic until translucent. Add Italian seasoning. Add the tomato paste and cook 3 minutes. Add the sausage and break it up until it's in as small pieces as possible, works great with a potato masher. Add the crushed tomatoes. Bring to a simmer and cook 15 minutes season with salt and pepper. Meanwhile cook the lasagna noodles in boiling salted water and drain and let cool down a bit.
Coat the bottom of 9 x13 pan with 1 cup sauce. Mince the green pepper in a food processor and set aside. Mix 1 cup mozzarella cheese, ricotta cheese, and parmesan cheese together and set aside.
Coat the bottom of 9 x13 pan with 1 cup sauce. Mince the green pepper in a food processor and set aside. Mix the cheeses together and set aside.
Lay out the lasagna noodles on waxed paper. Spread 1/4 cup cheese mixture over each noodle, top with 1 tbsp. green pepper 5 pepperoni and 2 tbsp. sauce.
Roll up lasagna noodles and place seam side down in baking pan. Top with remaining sauce and the other 2 cups mozzarella cheese cover with foil and bake at 350 degrees for about an hour.